Did a range test a long time ago with an indoor range out to 175ft. We were trying to get an idea about how accuracy degrades with distance. The test ran with a full length M16A3 barrel a M4 length and a CQBR. I will have to look up the results and post a link about it. Both the full length and the M4 did well out to almost 200ft but the cqbr was about half that.
I would say 200ft is about the max that I have ever seen a gun shoot out to, and at that distance the bb is floating like a leaf in the wind. If someone says they have a gun that will shoot 100yd (300ft) at game acceptable fps limits, I call BS.
I have found that airsofters in general have no accurate concept of distance.